This application relates to copending application Ser. No. 995,281 filed herewith for "A Method and System for Automatically Inspecting Ophthalmic Lenses," to copending application Ser. No. 994,565 filed herewith for "Illumination and Imaging Subsystems for a Lens Inspection System," to copending application Ser. No. 995,654 filed herewith for "A Method of Inspecting Ophthalmic Lenses," and to copending application Serial No. 994,654 filed herewith for "A Lens Inspection System."
This invention generally relates to carriers for ophthalmic lenses, and more particularly, to lens carriers that are especially well suited for holding contact lenses while the lenses are being inspected.
Contact lenses are, typically, made with a high degree of precision and accuracy. Nevertheless, on rare occasions, a particular lens may contain an irregularity; and for this reason, contact lenses are inspected before sale to the consumer to be certain that the lenses are acceptable for consumer use.
In one type of prior art lens inspection system, the lenses are placed in small cups or wells and moved through a lens inspection position, where an illuminating beam is transmitted through each lens. That illuminating beam is then focused on a screen to produce thereon an image of the lens, and an operator looks at that image to determine if the lens contains any irregularities. If any irregularity or flaw is found that makes the lens unsuitable for consumer use, then the lens is either removed from the inspection system or otherwise identified so that it is not subsequently sold to a consumer.
The lens carrier is an important element of this inspection system. In particular, it is important to minimize the affect that the lens carrier has on the illuminating beam transmitted through the ophthalmic lenses, because disturbances in that illuminating beam that are caused by the lens carrier may be interpreted by the operator as an irregularity in the lens being inspected.
In addition, it is highly advantageous that the lens carrier be readily disposable. This is so because if a lens carrier is reused, small scratches may be made on the carrier, and these scratches may deflect or refract part of the illuminating beam used to inspect the ophthalmic lenses. An operator may observe the image produced by this deflected or refracted light and interpret it as an irregularity or flaw in the lens being inspected.
Despite the above-mentioned considerations, the prior art lens inspection systems of the above-discussed general type are very effective and reliable; however, these systems are also comparatively slow and expensive. This is so because a human operator must focus on the lens image produced on the screen and check that whole image for any irregularity. It is thus believed that the prior art systems can be improved upon; and in particular, it is believed that the cost of the lens inspection can be reduced and the speed of the inspection can be increased by providing an automated system to perform these inspections.
In any automated system, it is important that the lens be positioned precisely relative to the illuminating beam that is transmitted through the lens. This, in turn, requires that the lens carrier--in addition to meeting the criteria discussed above--hold the lens in a well defined position as the carrier is moved through the system, and also be precisely movable over a given pattern or path.